Voltage control apparatus



Oct. 7, 1947. w. c. ANDERSON 2,428,693

VOLTAGE CONTROL ArmnA'rus Filed Jan. 19, 1946 W RE-l r //3 A? cc /5 /4'VT? za VT-l8r2 n HEATERS 2/ &

BI+ l VT-3 AMPLIFIER 2? T RS HEA E INVENIDR I Wilmer C. Anderson BY W 2:2;; KY

Patented Oct. 7, 1947 VOLTAGE CONTROL APPARATUS Wilmer C. Anderson,Douglaston, N. Y., assignor to Arma Corporation, Brooklyn, N. Y., acorporation of New York Application January 19, 1946, Serial No.642,255-

14 Claims. (01-. 175-363) This invention relates to voltage controlapparatus, and has particular reference to automatic means for effectingaccurate regulation of a plurality of voltage supplies from a singlesource, such as all of the tube filament, grid and plate supply outputsof a power-pack for electronic mechanical servo-systems.

In electronic servo-systems utilizing the char acteristics of vacuumtubes in accurate mathematical calculations, it is important that thevoltage supply to many points be accurate and uniform. Electronicsystems of voltage control are known to the art which are accurate andreliable, but the power which they can handle is decidedly limited.Saturated core reactors, on the other hand, are capable of handlinggreat power, but are not reliable, by themselves.

In accordance with the present invention, an automatic voltage controlapparatus is provided, which supplies uniform and accurate voltages tomany points and aifords great power with utmost reliability "at alltimes, so that the control apparatus of this invention is safelyadaptable for use in making mathematical calculations for purposesrequiring great accuracy.

The invention combines in a novel way the advantage of accuracy of anelectronic voltage control system with the great'power capacity of a.saturated core reactor, so that both accuracy and a multiplicity ofvoltage outputs result. In a preferred embodiment of the invention, asuitable electronic voltage regulator provides a relatively low powerconstant voltage as a standard, which is compared with the input voltageapplied to series windings on two legs of a saturable core reactor,whose third leg winding is supplied with any difference between theinput and standard voltage to thereby vary the output of the reactor.The reactor is used to vary the output voltage of the'entire controlsystem, preferably by application of the regulated voltage therefrom tothe primary windings of the input transformers supplying the variousloads, such as vacuum tubes and the like.

It will be seen that the voltage control systern of this inventionaffords large power output while maintaining the accuracy and constancyof a conventional low power electronic voltage regulator, and that thesedesirable results I are obtained by a simple arrangement involvingferred form of the invention, the parts thereof being represented byconventional electrical symbols.

Referring to the drawing, numeral I0 indicates a service connection to a115 volt, single-phase alternating supply which is subject to thevariation of supply voltage common to a commercial outlet. This supplyis fed to the assembly of transformers shown at H, the service lead [2feeding one side of each of the primary windings l5, l6 and ll oftransformers T1, T2 and T3 and the other service lead l3 feeding throughthe series windings l9 and 2| of the saturable core reactor RE|, whichis of conventional construction comprising a core l8 having threeinterconnected legs bearing windings I9, 20 and 2!. The return lead itis connected to the other side of primary windings l5, I6, I! oftransformers T1, T2, T3.

The secondary winding 22 of the step-down transformer T3 may beconnected to a pair of amplifier tube heater leads, not shown, and tothe usual pair of high-voltage secondary windings 23 and 24 of step-uptransformer T2. These are to supply the double-wave electronic rectifierVT--4, the positive side of which is connected to the pair of secondarywindings 25, 26 of transformer Tl whose common lead is connected throughthe choke CHI to the terminal B1+. The negative terminal of rectifierVT4 is connected by the grounded lead 21 to the B-terminal as shown.

In similar well-known manner, the primary winding ll of transformer T1induces in the various other secondary windings suitable heater voltagesfor .the vacuum tubes used, as indicated in the drawing. In addition tothe heater voltage secondary winding of transformer T1, another pair ofsecondary windings 28, 29 is provided for transformer Tl, in conformitywith this invention. These windings feed relatively high voltagesthrough the duplex rectifier tube VT| and resistors R,l, R2 andcondenser C4 to provide a direct current voltage at the point 30 for anindication of 'the relative value of all output voltages of thecomposite load of transformers Tl, T2, and T3 for a purpose to beexplained.

The final unit of the voltage-control apparatus of this invention isdesignated 3| and is adapted for producing across the terminals 32+ andB- an accurately regulated standard voltage of low power, to which thevoltage produced at point 30 is to be continuously conformed. The unit3| is of known construction comprising the parts shown and operating insuch a way as to cause the output voltage across 32--33 to besubstantially independent of the load impedance connected across 3233 orof the unregulated filtered direct current voltage input to the unit 3|.This is because any fluctuation in the output voltage across 3233 willvary the potential applied to the grid of type 6J7 tube VT-5, and

- hence the grid-cathode potential, since the regulating action oftwo-watt neon tube N keeps the cathode potential of tube VT5 constant.Any variation in output voltage is accordingly applied to tube VT-S and,after amplification thereby, affects the grid potential of 2A3 type tubeVT'3 so as to produce a change in voltage drop therein which opposes thechange in output voltage across 3233. The foregoing description ofvoltage regulator unit 3! is sufficient for an understanding of itsfunction in connection with the present invention, further details beingobtainable upon reference to page 615 and Fig. 19 of Termans RadioEngineers Handbook, published 1943 by McGraw Hill Co.

Across the output terminals 3233 of voltage regulator unit 3| arebridged in series the resistances RH and RH and from their junctionpoint 34 a lead 35 is connected to the point 30 on the grid of the tubeVT-2, which controls the how of current through the winding 20 on thecenter leg of the reactor REI in accordance with the voltage on itsgrid, and causes regulation of the input voltage from source it) toprimary windings 15, I6 and l! of transformers T1, T2, T3, in a wellknown manner.

The operation of the voltage control apparatus of this invention isreadily understood from the foregoing description and may be summarizedas follows: The voltage regulator unit 3|, regardless of variation ofvoltage of the power source l0, produces a standard direct currentvoltage which is predetermined by the ratio of re sistances RI 0, R7 andR8, and applies that standard voltage to the point 30, i. e. the grid ofthe tube VT-2. At the same time tube VT-l provides a sample directcurrent voltage proportional to the alternating current voltage of thepower source Ill and applies it also to point 30 but in opposite senseto the voltage supplied from unit 3i. When, therefore, the samplevoltage of the system applied at 30 from VT--l agrees with the standardvoltage from unit 3 I, also applied at 30, a predetermined current flowsin the regulating winding 20 of reactor RE-l. However, when the samplevoltage from tube VTI disagrees with the standard voltage from unit 3!,appropriate change in correction current will be passed by tube VT2through regulating winding 20 of reactor REl to vary the portion of thefull voltage source [0 which is applied to the primary windings l5, l6and ll of transformers T1, T2, T3. In this way, continuous and accuratecontrol of a heavy load is automatically accomplished by means of aregulator of a very light load, without requiring attention forindefinitely long periods.

Although a preferred embodiment of the invention has been illustratedand described herein, it is to be understood that the invention is notlimited thereby, but is susceptible of changes in form and detail withinthe scope of the appended claims.

I claim:

1. In voltage control apparatus wherein a relatively high-powercomposite load is applied to an alternating current source in serieswith a voltage input control means for said load, the combination of adelivery voltage measuring device, a relatively low-power constantvoltage standard comprising an electronic voltage regulator, comparingmeans responsive to any difference in magnitude and sense between thevoltage output of said voltage measuring device and the constant voltageof said voltage standard, and means energized by the difference outputof said comparing means and interposed between said source and load,whereby said control apparatus is caused to operate in accordance withsaid voltage comparison to regulate the voltage applied to saidrelatively high-power load.

2. In a voltage control apparatus wherein a relatively high-powercomposite load is applied to an alternating current source in serieswith a voltage input control means, the combination of a voltageregulator connected to said source for producing a relatively low powerconstant voltage, a winding interposed between said source and saidload, a rectifier connected to said source, comparing means responsiveto any difference in magnitude and sense between the output voltages ofsaid regulator and rectifier, and a second winding in electricalrelation to said first winding and connected to said responsive means,whereby said control apparatus is caused to operate in accordance withsaid voltage comparison to regulate the voltage applied to saidrelatively high power loads.

3. In voltage control apparatus wherein a. relatively high-powercomposite load is applied to an alternating current source in serieswith a voltage input control means, the combination of a. voltageregulator connected to said source for producing a relatively low powerconstant voltage, a saturable core having a winding interposed betweensaid source and said load, a rectifier connected to said source,comparing means responsive to any difference in magnitude and sensebetween the output voltages of said regulater and rectifier, and asecond winding on said core and connected to said responsive means,whereby said control apparatus is caused to operate in accordance withsaid voltage comparison to regulate the voltage applied to saidrelatively high power load.

4. In a voltage control apparatus wherein a relatively high-powercomposite load is applied to an alternating current source in serieswith a voltage input control means, the combination of a voltageregulator connected to said source for producing a relatively low powerconstant voltage, an input transformer having a primary windingconnected to said source and a secondary winding, a winding interposedbetween said source and said primary winding, a rectifier connected tosaid secondary winding, comparing means responsive to any difference inmagnitude and sense between the output voltages of said regulator andrectifier, and a second windin in electrical relation to said firstwinding and connected to said responsive means, whereby said controlapparatus is caused to operate in accordance with said voltagecomparison to regulate the voltage applied to said relatively high powerloads.

5. In a voltage control apparatus wherein a relatively high-powercomposite load is applied to an alternating current source in serieswith a voltage input control means, the combination of a voltageregulator connected to said source for producing a relativel low powerconstant voltage, a winding interposed between said source and saidload, a rectifier connected to said source, a pair of series resistancesbridged across the output of said regulator, comparing means interposedbetween the output of said rectifier and a point between saidresistances and responsive to any difference in magnitude and sensebetween the output voltages of said regulator and rectifier, and asecond winding in electrical relation to said first winding andconnected to said responsive means, whereby said control apparatus iscaused to operate in accordance with said voltage comparison to regulatethe voltage applied to said relatively high power loads.

6. In voltage control apparatus wherein a relatively high-powercomposite load is applied to an alternating current source in serieswith a voltage input control means, the combination of a voltageregulator connected to said source for producing a relatively low powerconstant voltage, an input transformer having a primary windingconnected to said source and a secondary winding, a saturable corehaving a winding interposed between said source and said primarywinding, a rectifier connected to said primar winding, comparing meansresponsive to any difference in magnitude and sense between the outputvoltages of said regulator and rectifier, and a second winding on saidcore and connected to said responsive means, whereby said controlapparatus is caused to operate in accordance with said voltagecomparison to regulate the voltage applied to said relatively high powerload.

7. In voltage control apparatus wherein a relatively high-powercomposite load is applied to an alternating current source in serieswith a voltage input control means, the combination of a voltageregulator connected to said source for producing a relatively low powerconstant voltage, a saturable core having a winding interposed betweensaid source and said load, a rectifier connected to said source, a pairof series resistances bridged across the output of said regulator,comparing means interposed between the output of said rectifier and apoint between said resistances and responsive to any difference inmagnitude and sense between the output voltages of said regulator andrectifier, and a second winding on said core and connected to saidresponsive means, whereby said control apparatus is caused to operate inaccordance with said voltage comparison to regulate the voltage appliedto said relatively high power load.

8. In a voltage control apparatus wherein a relatively high-powercomposite load is applied to an alternating current source in serieswith a voltage input control means, the combination of a voltageregulator connected to said source for producing a relatively low powerconstant voltage, an input transformer having a primary windingconnected to said source and a secondary winding, a saturable corehaving a winding interposed between said source and said primarywinding, a rectifier connected to said secondary winding, comparingmeans responsive to any difference in magnitude and sense between theoutput voltages of said regulator and rectifier, and a second winding onsaid core and connected to said responsive means, whereby said controlapparatus is caused to operate in accordance with said voltagecomparison to regulate the voltage applied to said relatively high powerloads.

9. In a voltage control apparatus wherein a relatively high-powercomposite load is applied to an alternating current source in serieswith a voltage input control means, the combination of a said rectifierand a point between said resistances and responsive to any difference inmagnitude and sense between the output voltages of said regulator andrectifier, and a second winding in electrical relation to said firstwinding and connected to said responsive means, whereby said controlapparatus is caused to operate in accordance with said voltagecomparison to regulate the voltage applied to said relatively high powerloads.

10. In a voltage control apparatus wherein a relatively high-powercomposite load is applied to an alternating current source in serieswitha voltage input control means, the combination of a voltage regulatorconnected to said source for producing a. relatively low power constantvoltage, a saturable core having a windin interposed between said sourceand said load, a rectifier connected to said source, a pair of seriesresistances bridged across the output of said regulator, comparing meansinterposed between the output of said rectifier and a point between saidresistances and responsive to any difference in magnitude and sensebetween the output voltage of said regulator and rectifier, and a secondwinding on said core and connected to said responsive means, wherebysaid control apparatus is caused to operate in accordance with saidvoltage comparison to regulate the voltage applied to said relativelyhigh power loads.

11. In a voltage control apparatus wherein a relatively high-powercomposite load is applied to an alternating current source in serieswith a voltage input control means, the combination of a voltageregulator connected to said source for producing a relatively low powerconstant voltage, an input transformer having a primary windingconnected to said source and a secondary winding, a winding interposedbetween said source and said primary winding, a rectifier connected tosaid secondary winding, a pair of series resistances bridged across-theoutput of said regulator, comparing means interposed between the outputof said rectifier and a point between said resistances and responsive toany difference in magnitude and sense between the output voltages ofsaid regulator and rectifier, and a second winding in electricalrelation to said first winding and connected to said responsive means,whereby said control apparatus is caused to operate in accordance withsaid voltage comparison to regulate the voltage applied to saidrelatively high power loads.

12. In a voltage control apparatus wherein a relatively high-powercomposite load is applied to an alternating current source in serieswith a voltage input control means, the combination of a voltageregulator connected to said source for producing a relatively low powerconstant voltage, an input transformer having a primary Windingconnected to said source and a secondary winding, a saturable corehaving a winding interposed between said source and said primarywinding,

a rectifier connected to said secondar winding, a pair of seriesresistances bridged across the output of said regulator, comparing meansinterposed between the output of said rectifier and a point between saidresistances and responsive to any difference in magnitude and sensebetween the output Voltages of said regulator and rectifier, a secondwinding on said core and connected to said responsive means, wherebysaid control apparatus is caused to operate in accordance with saidvoltage comparison to regulate the voltage applied to said relativelyhigh power loads.

13. In combination with a direct current voltage regulator for analternating current source, an input transformer having a primarywinding connected to said source and a secondary winding, a saturablecore reactor having a winding interposed between said source and theprimary winding of said input transformer, a rectifier connected to thesecondary winding of said input transformer, means responsive to anydifference in magnitude and sense between the output voltages of saidregulator and rectifier, a second winding for said reactor, andconnections between said means and said second reactor winding, wherebythe voltage impressed on said primary winding is increased or decreasedin accordance with the correction voltage impressed by said secondreactor winding.

14. In combination with a direct current voltage regulator for analternating current source, an input transformer having a primarywinding connected to said source and a secondary winding, a saturablecore reactor having a winding interposed between said source and theprimary winding of said input transformer, a rectifier connected to thesecondary winding of said input transformer, a pair of seriesresistances bridged across the output of said regulator, meansinterposed between the output or said rectifier and a point between saidresistances and responsive to any difference in magnitude and sensebetween the output voltages of said regulator and rectifier, a secondwinding for said reactor, and connections between said means and saidsecond reactor winding, whereby the voltage impressed on said primarywinding is increased or decreased in accordance with the correctionvoltag impressed by said second reactor winding.

-WHlMER C. ANDERSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,118,644 Garman May 24, 19382,195,120 Moyer Mar. 26, 1940

